• Title/Summary/Keyword: $Si_3$$N_4$

검색결과 2,127건 처리시간 0.031초

하해혼성 평야지 논토양에서 유기물 장기 연용이 토양의 이화학적 특성 변화 및 질소 흡수에 미치는 영향 (Effect of Long-Term Annual Dressing of Organic Matter on Physico-Chemical Properties and Nitrogen Uptake in the Paddy Soil of Fluvio-Marine Deposit)

  • 양창휴;정지호;김택겸;김선;백남현;최원영;김영두;정원교;김시주
    • 한국토양비료학회지
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    • 제43권6호
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    • pp.981-986
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    • 2010
  • 본 연구는 비료 및 유기자원을 30년 연용한 전북통 (미사질양토) 논토양에서 수행하였다. 관행 (NPK), NPK+볏짚, NPK+볏짚퇴비와 질소 시비수준을 0, 100, 150, 200, 250 kg $ha^{-1}$로 처리하였으며 토양의 이화학성 변화 및 유기탄소 함량, 토양과 식물체의 질소 흡수를 조사 및 분석한 결과는 다음과 같다. 관행구 (NPK)에 비하여 NPK+볏짚퇴비구에서 토양경도는 15.7 mm에서 12.5 mm로, 용적밀도는 1.381 Mg $m^{-3}$에서 1.244 Mg $m^{-3}$로 유의하게 낮아지는 결과를 보이고 있어 볏짚퇴비 시용에 따른 물리성 개선효과가 인정되었다. 관행구에 비하여 NPK+볏짚퇴비구에서 유효인산 함량은 96 mg $kg^{-1}$에서 133 mg $kg^{-1}$으로, 유효규산 함량은 81 mg $kg^{-1}$에서 116 mg $kg^{-1}$로 유의하게 많아졌고 CEC는 9.8 $cmol_c\;kg^{-1}$ 에서 11.4 $cmol_c\;kg^{-1}$로 유의하게 높아지는 결과를 보이고 있어 볏짚퇴비 시용에 따른 화학성 개량효과가 인정되었다. 토양유기탄소 함량은 처리별 유의적인 차이가 있었으며 토양깊이 0~7.5 cm에서는 관행구에 비하여 NPK+볏짚구, NPK+볏짚퇴비구에서 유의적으로 높았다. 시비 질소흡수량은 관행구 (질소 시비수준 100 kg $ha^{-1}$)에 비하여 NPK+볏짚구 (질소 시비수준 250 kg $ha^{-1}$) 및 NPK+볏짚퇴비구 (질소 시비수준 200, 250 kg $ha^{-1}$)에서 유의하게 많아지는 결과를 나타냈다. 질소이용률은 관행구 (질소 시비수준 100 kg $ha^{-1}$)에 비하여 NPK+볏짚퇴비구 (질소 시비수준 100, 150 kg $ha^{-1}$)에서 유의하게 높아지는 결과를 나타냈다. 논토양에서 유기자원 시용은 물리성 개선 및 비옥도를 향상시켜 벼의 시비질소흡수량 증가로 질소이용률을 높이는데 크게 기여한 것으로 생각된다.

한국남부(韓國南部)의 백악기말(白堊紀末) 이후(以後)의 화성활동(火成活動)과 광화작용(鑛化作用)에 대(對)한 판구조론(板構造論)의 적용성(適用性) 연구(硏究)( I ) (Applicability of plate tectonics to the post-late Cretaceous igneous activities and mineralization in the southern part of South Korea( I ))

  • 민경덕;김옥준;윤석규;이대성;주승환
    • 자원환경지질
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    • 제15권3호
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    • pp.123-154
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    • 1982
  • Petrochemical, K-Ar dating, Sand Rb/Sr isotopes, metallogenic zoning, paleomagnetic and geotectonic studies of the Gyongsang basin were carried out to examine applicability of plate tectonics to the post-late Cretaceous igneous activity and metallogeny in the southeastern part of Korean Peninsula. The results obtained are as follows: 1. Bulgugsa granitic rocks range from granite to adamellite, whose Q-Ab-Or triangular diagram indicates that the depth and pressure at which the magma consolidated increase from coast to inland varying from 6 km, 0.5-3.3 kb in the coastal area to 17 km, 0.5-10 kb in the inland area. 2. The volcanic rocks in Gyongsang basin range from andesitic to basaltic rocks, and the basaltic rocks are generally tholeiitic in the coastal area and alkali basalt in the inland area. 3. The volcanic rocks of the area have the initial ratio of Sr^{87}/Sr^{86} varying from 0.706 to 0.707 which suggests a continental origin; the ratio of Rb/Sr changing from 0.079-0.157 in the coastal area to 0.021-0.034 in the inland area suggests that the volcanism is getting younger toward coastal side, which may indicate a retreat in stage of differentiation if they were derived from a same magma. The K_2O/SiO_2 (60%) increases from about 1.0 in the coastal area to about 3.0 in the inland area, which may suggest an increase indepth of the Benioff zone, if existed, toward inland side. 4. The K-Ar ages of volcanic rocks were measured to be 79.4 m.y. near Daegu, and 61.7 m.y. near Busan indicating a southeastward decrease in age. The ages of plutonic rocks also decrease toward the same direction with 73 m.y. near Daegu, and 58 m.y. near Busan, so that the volcanism predated the plutonism by 6 m.y. in the continental interior and 4 m.y. along the coast. Such igneous activities provide a positive evidence for an applicability of plate tectonics to this area. 5. Sulfur isotope analyses of sulfide minerals from 8 mines revealed that these deposits were genetically connected with the spacially associated ingeous rocks showing relatively narrow range of ${\delta}^{34}S$ values (-0.9‰ to +7.5‰ except for +13.3 from Mulgum Mine). A sequence of metallogenic zones from the coast to the inland is delineated to be in the order of Fe-Cu zone, Cu-Pb-Zn zone, and W-Mo zone. A few porphyry type copper deposits are found in the Fe-Cu zone. These two facts enable the sequence to be comparable with that of Andean type in South America. 6. The VGP's of Cretaceous and post Cretaceous rocks from Korea are located near the ones($71^{\circ}N$, $180^{\circ}E$ and $90^{\circ}N$, $110^{\circ}E$) obtained from continents of northern hemisphere. This suggests that the Korean peninsula has been stable tectonically since Cretaceous, belonging to the Eurasian continent. 7. Different polar wandering path between Korean peninsula and Japanese islands delineates that there has been some relative movement between them. 8. The variational feature of declination of NRM toward northwestern inland side from southeastern extremity of Korean peninsula suggests that the age of rocks becomes older toward inland side. 9. The geological structure(mainly faults) and trends of lineaments interpreted from the Landsat imagery reveal that NNE-, NWW- and NEE-trends are predominant in the decreasing order of intensity. 10. The NNE-trending structures were originated by tensional and/or compressional forces, the directions of which were parallel and perpendicular respectively to the subduction boundary of the Kula plate during about 90 m.y. B.P. The NWW-trending structures were originated as shear fractures by the same compressional forces. The NEE-trending structures are considered to be priginated as tension fractures parallel to the subduction boundary of the Kula plate during about 70 m.y. B.P. when Japanese islands had drifted toward southeast leaving the Sea of Japan behind. It was clearly demonstrated by many authors that the drifting of Japanese islands was accompanied with a rotational movement of a clock-wise direction, so that it is inferred that subduction boundary had changed from NNE- to NEE-direction. A number of facts and features mentioned above provide a suite of positive evidences enabling application of plate tectonics to the late Cretaceous-early Tertiary igneous activity and metallogeny in the area. Synthesizing these facts, an arc-trench system of continental margin-type is adopted by reconstructing paleogeographic models for the evolution of Korean peninsula and Japan islands. The models involve an extention mechanism behind the are(proto-Japan), by which proto-Japan as of northeastern continuation of Gyongsang zone has been drifted rotationally toward southeast. The zone of igneous activity has also been migrated from the inland in late-Cretaceous to the peninsula margin and southwestern Japan in Tertiary.

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Echinostome Infections in the Striped-Field Mouse, Apodemus agrarius, and the Ussuri White-Toothed Shrew, Crocidura lasiura, Caught Near the Demilitarized Zone, Gyeonggi-do (Province), Republic of Korea

  • Chai, Jong-Yil;Park, Jae-Hwan;Jung, Bong-Kwang;Guk, Sang-Mee;Kim, Jae-Lip;Shin, Eun-Hee;Klein, Terry A.;Kim, Heung-Chul;Chong, Sung-Tae;Baek, Luck-Ju;Song, Jin-Won
    • Parasites, Hosts and Diseases
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    • 제47권3호
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    • pp.311-314
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    • 2009
  • A total of 1,498 small mammals (rodents and insectivores), including Apodemus agrarius (n= 1,366), Crocidura lasiura (54), Mus musculus (32), Micronytus fortis (28), Eothenomys regulus (9), Micronys minutes (6), and Cricetulus triton (3), were live-trapped in Gyeonggi-do (Province) (Paju-si, Pocheon-gun, and Yeoncheon-gun) near the demilitarized zone (DMZ) from December 2004 to September 2005. A. agrarius was found to be infected with 3 species of echinostomes (Echinostoma hortense, Echinostoma cinetorchis, and Euparyphium murinum), while C. lasiura was infected with 1 species (Echinochasmus japonicas) of echinostome. Other mammals were free from echinostome infections. Total 16 E. hortense were detected in 7 (0.5%) mice, 9 E. cinetorchis from 5 (0.4%), and 3 E. murinum from 2 (0.1%) out of 1.366 A. agrarius examined. E. japonicus was found only in 1 (1.9%; total 3 specimens) C. lasiura. These results demonstrate that A. agrarius and C. lasiura, inhabiting near the DMZ of Gyeonggi-do serve as the natural definitive hosts for several species of echinostomes, although their infection rates are low. This is the first record of natural infections of A. agrarius with E. cinetorchis and C. lasiura with E. japonicus in the Republic of Korea.

제주시 지역 일부 초등학교 비만아동의 간식 섭취 실태 (Study on snack intakes in obese elementary students in Jeju city)

  • 고양숙;이유영;채인숙;이윤경;제갈윤석;박형근
    • Journal of Nutrition and Health
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    • 제50권1호
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    • pp.85-97
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    • 2017
  • 본 연구는 제주시 지역 일부 초등학교 4 5학년 비만아동 117명 (남자 70명, 여자 47명)과 정상체중아동 117명 (남자 70명, 여자 47명)을 대상으로 일반사항, 체중감량 관련 식행동, 간식 식습관을 조사하였으며, 더불어 24시간 회상법을 이용하여 식이섭취실태를 파악함으로써 초등학교 고학년 학생들의 간식섭취 및 균형 잡힌 영양소섭취를 위한 교육자료 개발을 위한 기초자료를 제공하고자 하였으며, 연구결과는 다음과 같다. 조사대상자의 평균 신장, 체중 및 비만도는 각각 정상체중아동은 143.8 cm, 38.5 kg, -0.42%이며 비만아동은 147.5 cm, 56.6 kg, 35.4%로 모두 체중군에 따라 유의한 차이가 있었으나, 체중군별 열량 섭취량은 유의적인 차이를 보이지 않았다. 하지만 조사대상자의 체중감량 관련 식행동에서 식사량 감소 경험 유무와 살찌는 음식임을 고려하여 섭취하는 비율은 체중군별 유의적인 차이를 보였다. 조사대상자의 총 열량 섭취 열량은 아침, 점심, 저녁, 간식이 각각 289.8 kcal, 569.0 kcal, 499.2 kcal, 325.1 kcal로, 끼니별 열량 섭취 비율은 17.2%, 33.8%, 29.7%, 19.3%로 나타났다. 특히 간식으로 섭취하는 열량은 체중군별 유의적 차이는 없었으나, 특정 간식 음식을 섭취한 아동만을 대상으로 분석하였을 때, 비만군이 정상체중군에 비해 사탕 초콜릿류를 유의적으로 더 많이 섭취하고 있었다. 성별과 체중군별로 간식을 섭취하는 이유로는 공통적으로 '배가 고파서'가 64.1%, '심심해서'는 12% 순으로 나타났다. 간식 섭취 횟수에서 일반 간식의 경우 정상체중군 (2.1회/주)이 비만군 (1.6회/주)보다 자주 섭취하는 것으로 나타났고, 학교나 학원 주변에서 섭취하는 간식의 경우에는 체중군별 차이 (1회/주)가 없었다. 일반 간식과 학교나 학원 주변 간식을 합한 총간식의 섭취 횟수는 정상체중군은 3.1회/주, 비만군은 2.6회/주로 나타났다. 일반 간식에서 자주 먹는 간식 음식은 과일 과일주스, 과자 사탕 초콜릿, 우유 요구르트 순으로 높게 나타났고, 학교나 학원 주변 간식에서는 김밥 삼각김밥 떡볶이 순대, 아이스크림, 과자 사탕 초콜릿의 순으로 높게 나타났으며, 체중군별 간식 선택 음식의 종류에는 유의적 차이가 없었다. 하지만 간식음식을 저열량 고영양 간식과 고열량 저영양 간식으로 구분하고, 간식 음식선택 여부와 섭취 횟수를 고려한 섭취 수준으로 비교하였을 때에는 비만군이 정상체중군보다 저열량 고영양 간식의 섭취수준이 유의적으로 낮게 나타났다. 이상의 결과를 종합해 볼 때 본 제주의 일부 초등학교 5, 6학년 학생들은 체중군별로 비만군이 정상체중군에 비해 체중 감량을 위해 더 노력하지만, 비만군이 정상체중군보다 저열량 고영양 간식을 유의적으로 낮게 섭취하는 것을 알 수 있었다. 고열량 저영양의 부적절한 종류의 간식음식의 섭취는 하루 세끼 식사에 영향을 미치고, 영양 불균형을 초래할 수 있으므로 비만군 뿐만 아니라 정상체중군에서도 올바른 간식 선택 및 식행동 개선을 위한 영양교육이 필요하다고 사료된다. 균형 잡힌 하루 세끼 식사를 충분히 섭취한 후, 부족한 부분을 간식으로 보충할 수 있도록 영양적인 측면과 관련지어 간식 섭취에 대한 적절한 교육이 학교에서 뿐만 아니라 가정연계를 통해 체계적으로 전개되어야 하겠다.

한국산 그물베도라치(Dictyosoma burgeri)의 산란행동 유도 및 난 발생과 자어의 형태발달 (Spawning Behavior and Morphological Development of the Eggs and Larvae of the Blennioid Fish, Dictyosoma burgeri from Korea (Pisces: Stichaeidae))

  • 박재민;한경호;김나리;홍창기;박종연;조재권
    • 한국어류학회지
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    • 제26권2호
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    • pp.112-117
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    • 2014
  • 이 연구는 우리나라에 서식하는 그물베도라치의 산란행동과 난 발생 및 자어의 형태발달을 조사하여 분류학적 연구의 기초자료로 이용하고자 실시하였다. 수정란은 구형으로 백색의 불투명한 침성 점착란이었고, 유구의 수는 3~4개였으며, 난의 크기는 1.31~1.47mm(평균 $1.38{\pm}0.05mm$, n=10) 범위였다. 유구의 크기는 0.12~0.38 mm (평균 $0.25{\pm}0.10mm$, n=10)였다. 사육수온은 $14.5{\sim}16.5^{\circ}C$ (평균 $15.0{\pm}0.05^{\circ}C$)를 유지하였고, 난 발생 과정은 64세포기 후 30시간이 경과하여 상실기에 달하였으며, 64세포기 후 744시간이 경과하여 머리 윗부분이 난막을 뚫고 나오면서 부화가 시작되었다. 부화직후의 자어는 전장 7.10~7.60mm(평균 $7.34{\pm}0.18mm$)로 입은 열려 있었고, 부화 후 6일째의 후기 자어는 전장 9.06~9.13 mm (평균 $9.10{\pm}0.02mm$)로 꼬리지느러미의 윗부분에 줄기가 분화하기 시작하였고, 난황은 모두 흡수되었으며, 먹이 섭식활동을 시작하였다.

자기성장 프로그램이 초등학생의 자아개념과 또래관계에 미치는 효과 (The Effect of Self-Growth Program on the Self-Concept and Peer-Relationship of Elementary School Student)

  • 김태희
    • 초등상담연구
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    • 제4권1호
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    • pp.215-236
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    • 2005
  • The Purpose of this study is that self-growth program searches effect self-concept and peer-relationship with elementary school student, and advance following assumption to achieve this purpose and achieved study. First, self-concept point of experiment group students who execute self-growth program will be improved is meaning than self-concept point of control group students. Second, peer-relationship point of experiment group students who execute self-growth program will be improved is meaning than peer-relationship point of control group students. Third, effect that self-growth program gets to self-concept may be meaning difference according to sex. Fourth, difference that impact that self-growth program gets in peer- relationship is meaning according to sex may join. Chose fifth-year student 2 class 68 people (experiment group n=34, control group n=34) in I primary school locating to Jeonrabuk-do Iksan-si to verify above construction for study target. Disposal about experiment group executed over 10th for 60-80 minute 2 times in a week because investigator uses reconstructing self-growth program with virtue research paper such as learning program for own growth of Lee-Hyeong-Deuk (1998). In order to verify the effect after experiment, 1 collected materials for estimation by providing the subject children with questionaires about self-concept and peer-relationship before and after the experiment, and then analyzed the average differences in number of marks between the experiment group and the control group before and after the experiment through and by using One-Way ANOVA, and SPSS 11.0 program. The following is the result what I obtained from the above study. First, there was significant difference is between average difference before and after of experiment group and control group which execute self-growth program in self-concept elevation ($F_{(1,66)} =28.734$, p <.001). From the sub-variable, there was significant difference in academic self ($F_{(1,66)}=6.423$, p<.05), Social Self ($F_{(1,66)}=48.331$, p<.001), Physical Self ($F_{(1,66)}=11.074$, p <.01), sentimental self ($F_{(1,66)}=9.402$, p <.01) Second, there was significant difference is average difference before and after of experiment group and control group which execute self-growth program in peer-relationship promotion ($F_{(1,66)}=24.109$, p <.001). From the sub-variable there W3S Significant difference in trust ($F_{(1,66)}=14.507$, p<.001), respect ($F_{(1,66)}=15.271$, p <.001). Third, there was expose that significant difference does not exist in average self-concept before and after by sex of experiment group which executes self-growth program, and was not shown significant difference in sub-vairable. Fourth, there was expose that significant difference of whole peer- relationship and in respect of sub-variable in average peer-relationship before-after by sex of experiment group which execute self-growth program, but significant difference did not appear in trust. Could get conclusion that self-growth program is effect in elementary school student self-concept elevation and peer-relationship promotion according to these study finding, and confirmed possibility that self-growth program may contribute to change emotional special quality of children positively in education spot.

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Effects of Granular Silicate on Watermelon (Citrullus lanatus var. lanatus) Growth, Yield, and Characteristics of Soil Under Greenhouse

  • Kim, Young-Sang;Kang, Hyo-Jung;Kim, Tae-Il;Jeong, Taek-Gu;Han, Jong-Woo;Kim, Ik-Jei;Nam, Sang-Young;Kim, Ki-In
    • 한국토양비료학회지
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    • 제48권5호
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    • pp.456-463
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    • 2015
  • The objective of this study was to determine the effects of granular type of silicate fertilizer on watermelon growth, yield, and characteristics of soil in the greenhouse. Four different levels of silicate fertilizer, 0(control), 600, 1,200, $1,800kg\;ha^{-1}$ were applied for experiment. The silicate fertilizer was applied as a basal fertilization before transplanting watermelon. Compost and basal fertilizers were applied based on the standard fertilizer recommendation rate with soil testing. All of the recommended $P_2O_5$ and 50% of N and $K_2O$ were applied as a basal fertilization. The N and $K_2O$ as additional fertilization was split-applied twice by fertigation method. Watermelon (Citrullus lanatus Thunb.) cultivar was 'Sam-Bok-KKuol and main stem was from rootstock (bottle gourd: Lagenaria leucantha Standl.) 'Bul-Ro-Jang-Sang'. The watermelon was transplanted on April, 15. Soil chemical properties, such as soil pH, EC, available phosphate and exchangeable K, Mg, and available $SiO_2$ levels increased compared to the control, while EC was similar and the concentrations of soil organic matter decreased. Physical properties of soils, such as soil bulk density and porosity were not different among treatments. The growth characteristics of watermelon, such as stem diameter, fresh and dry weight of watermelon at harvest were thicker and heavier for silicate treatment than the control, while number of node was shorter than the control. Merchantable watermelon increased by 3-5% compared to the control and sugar content was 0.4 to $0.7^{\circ}Brix$ higher than the control. These results suggest that silicate fertilizer application in the greenhouse can improve some chemical properties of soils and watermelon stem diameter and dry weight, which are contributed to watermelon quality and marketable watermelon production.

Tribological study on the thermal stability of thick ta-C coating at elevated temperatures

  • Lee, Woo Young;Ryu, Ho Jun;Jang, Young Jun;Kim, Gi Taek;Deng, Xingrui;Umehara, Noritsugu;Kim, Jong Kuk
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.144.2-144.2
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    • 2016
  • Diamond-like carbon (DLC) coatings have been widely applied to the mechanical components, cutting tools due to properties of high hardness and wear resistance. Among them, hydrogenated amorphous carbon (a-C:H) coatings are well-known for their low friction properties, stable production of thin and thick film, they were reported to be easily worn away under high temperature. Non-hydrogenated tetrahedral amorphous carbon (ta-C) is an ideal for industrial applicability due to good thermal stability from high $sp^3$-bonding fraction ranging from 70 to 80 %. However, the large compressive stress of ta-C coating limits to apply thick ta-C coating. In this study, the thick ta-C coating was deposited onto Inconel alloy disk by the FCVA technique. The thickness of the ta-C coating was about $3.5{\mu}m$. The tribological behaviors of ta-C coated disks sliding against $Si_3N_4$ balls were examined under elevated temperature divided into 23, 100, 200 and $300^{\circ}C$. The range of temperature was setting up until peel off observed. The experimental results showed that the friction coefficient was decreased from 0.14 to 0.05 with increasing temperature up to $200^{\circ}C$. At $300^{\circ}C$, the friction coefficient was dramatically increased over 5,000 cycles and then delaminated. These phenomenon was summarized two kinds of reasons: (1) Thermal degradation and (2) graphitization of ta-C coating. At first, the reason of thermal degradation was demonstrated by wear rate calculation. The wear rate of ta-C coatings showed an increasing trend with elevated temperature. For investigation of relationship between hardness and graphitization, thick ta-C coatings(2, 3 and $5{\mu}m$) were additionally deposited. As the thickness of ta-C coating was increased, hardness decreased from 58 to 49 GPa, which means that graphitization was accelerated. Therefore, now we are trying to increase $sp^3$ fraction of ta-C coating and control the coating parameters for thermal stability of thick ta-C at high temperatures.

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물성을 달리한 삼치(Scombermorus niphonius) 활용 고령친화식품의 제조 및 품질특성 (Preparation and Quality Characteristics of Japanese Spanish Mackerel Scombermorus niphonius Processed Products with Different Physical Properties as Senior-friendly Seafoods)

  • 박선영;이석민;박시형;강상인;장미순;김진수
    • 한국수산과학회지
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    • 제55권2호
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    • pp.111-120
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    • 2022
  • This study was conducted to prepare braised product with soy sauce (BP), rose gratin (RG) and white mousse (WM) using Japanese Spanish mackerel Scombermorus niphonius as senior-friendly seafoods with different physical and nutritional properties and to examine their quality characteristics. The hardness of BP, RG and WM were 428.0×103, 46.9×103 and 16.0×103 N/m2, respectively. The nutritional values of BP, RG and WM are 17.8, 9.1 and 18.5 g, respectively, for protein; 11.86, 23.32 and 13.35 ㎍ RAE, respectively, for vitamin A; 1.27, 0.49 and 0.17 ㎍, respectively, for vitamin D; 45.21, 12.79, and 35.54 mg, respectively, for vitamin C; 0.17, 0.13 and 0.23 mg, respectively, for riboflavin; 4.28, 2.94 and 3.65 mgNE, respectively, for niacin; 19.6, 104.0 and 48.1 mg, respectively, for Ca; 441.6, 271.1 and 250.1 mg, respectively, for K; 0.20, 0.80 mg and undetection, respectively, for dietary fiber. Escherichia coli was undetected in all the products. These results indicated that the products be classified as steps 1 for BP, step 2 for RG and step 3 for WM of senior-friendly seafoods based on the KS, and as nutritional and physical properties-improved senior-friendly seafoods based on the Food Code.

열선 화학 기상 증착법에 의한 실리콘 박막 및 태양전지 특성 (Silicon thin films and solar cells by HWCVD)

  • 김상균;이정철;전상원;임충현;안세진;윤재호;김석기;송진수;박성주;윤경훈
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 춘계학술대회
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    • pp.205-208
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    • 2005
  • 최근 열선 화학 기상 증착법(HWCVD)은 낮은 온도에서 TFT용 Poly Si 중착을 할 수 있다는 점과 실리콘 박막을 빠른 속도로 증착할 수 있다는 점에서 각광을 받고 있다. 본 연구에서는 HWCVD를 이용하여 태양전지를 제조하고 그 특성을 평가하였다. 조건에 따른 실리콘 박막의 특성 변화를 알기 위해 corning glass 및 실리콘 wafer에 다양한 조건에서 단위 박막(intrinsic layer)을 증착하였고 이 결과를 바탕으로 p/i/n 구조의 태양전지를 제조하였다. Ta 열선 온도는 1700-2000도였고 가스 원료인 $SiH_4$와 수소의 비율을 조절하면서 그 영향을 관찰하였다. 태양전지의 경우 p충과 n충은 PECVD로 증착하였으며 단위박막 및 태양전지 i충 증착시 기판과 열선간의 거리는 7cm, 기판 온도는 $200^{\circ}C$$250^{\circ}C$로 고정하였고 작업압력은 30mTorr였다. 단위 박막 특성 평가를 위해 암/광 전도도, SEM, Raman Scattering, FT-IR등을 사용하였으며 태양전지 특성 평가를 위해 I-V 및 Spectral response를 측정하였다. 열선 온도가 증가함에 따라 증착속도 및 결정화 분율은 증가하였다. 특히 비정질에서 결정질로 전이되는 구간은 매우 좁았으며 여러 분석 방법에서 일치되는 결과를 보였다. $SiH_4$ 유량이 늘어날수록 비정질이 결정질로 바뀌는 열선 온도가 증가하였으며 기판 온도가 낮을 경우 또한 결정으로 바뀌는 열선 온도가 증가하였다. 태양전지의 경우 열선 온도가 증가함에 따라 $V_{oc}$ 및 W가 낮아졌으며 $J_{sc}$, 는 증가하는 경향을 보였으며 결정질 비율이 증가하는 것을 관찰할 수 있었다. 이러한 경향은 quantum efficiency 결과에서도 확인할 수 있었다.용을 반복하면서 석재 내부와 외부의 암석 및 결정에 균열과 미세열극 등이 생성되어 석재 자체의 구조적 안정성에 영향을 주고 있다. 따라서 감은사지 석탑은 지리적 환경 차이로 인해 일반적인 환경의 석조물들과는 다른 형태의 풍화양상을 보이고 있어서 풍화양상 및 풍화형태에 대한 정확한 연구와 이해를 바탕으로 보존대책이 마련되어야 한다.되었다. 이런 모든 시편들을 각 탈염방법에 따라 탈염처리한 후 XRD와 SEM-EDS으로 분석한 결과 인철광과 침철광은 어떠한 변화도 보이지 않았고, 다만 적금광으로 동정된 시편만이 잔존하지 않았다. 철기 제작별 $Cl^-$ 이온 추출량과 탈염효과에 대한 비교 실험은 이온 크로마토그래피 분석 결과와 마찬가지로 단조 철제유물이 주조 철제보다 $Cl^-$ 이온을 많이 가지고 있었으며, 탈염 처리 후에는 $Cl^-$ 이온은 전혀 발견되지 않았다. 이상의 결과 $K_2CO_3$와 Sodium 용액은 탈염처리에서 가장 적합한 탈염처리 용액으로 알수가 있었으며 특히 어떠한 탈염 용액으로 유물을 처리한다 해도 철제유물에 생성된 부식물은 제거되지 않는다는 것을 알게 되었다. 따라서 보존처리자는 유물 표면의 부식 상태만을 보고 처리하기 보다는 철기제작물로 고려하여 처리하는 것이 필요하다. 또한 금속에 부식을 야기시키는 $Cl^-$ 이온과 부식물을 완전하게 제거하여 탈염처리를 하는 것이 유물 부식을 최대한 지연시킬 수 있는 것이라 생각된다.TEX>$88\%$)였다.(P=0.063). 결론: 본 연구에서는 MTHFR C/T & T/T 유전자 다형성이 위암의 발생과 그 위치에 대해 관련이 있는 것으로 여겨지고, 흡연력, 음주력과는 관련이 없는 것으로 여겨진다.험이 커지는 경향을 보였으나, 나이 및 병기, 종양의 크기, MD-BED $Gy_{10}$ 등의 예후 인자를 보정한 다변

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